Traegaardhia dalmatina ( Willmann, 1939 ), 1980

Zacharda, Miloslav, Fong, Daniel, Hobbs Iii, Horton H., Piva, Erminio, Slay, Michael E. & Taylor, Steven J., 2010, 2474, Zootaxa 2474, pp. 1-64 : 8-13

Traegaardhia dalmatina ( Willmann, 1939) ( Figs 2–5)

Rhagidia dalmatina Willmann, 1939 , Zoologischer Anzeiger, 125, 244.

Rhagidia longipes: Cooreman, 1959 , Notes sur quelques acariens de la faune cavernicole (2 me Serie).

Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 35(34), 18–19.

Traegaardhia dalmatina ( Willmann, 1939) Zacharda, 1980 , Acta Universitatis Carolinae, Biologica, (1978), 715–719. Rhagidia gigas longipes Trägardh, 1912 , Archives de Zoologie Experimentale et Generale, Sér. 5, 8, 608–611.

Material examined

Adult male, France, Ariège , Saint-Girons , Gouffre du Plagnol de la Plagne Cave , coll. E. Piva, 17.8.1997, deposited in the Museum of Biological Diversity , Ohio State University , access number OSAL0007419; adult male and adult female, the same data, OSAL 0007420 and OSAL 0007421, respectively; adult male and adult female, Ariège , Saint-Girons, Petit Plagnol Cave, about 815 m a.s.l., coll. G. Peretto, E. Piva, 8.8.2001, preserved in ethanol in collection of M. Zacharda .

Diagnosis

Naso short. Prodorsal bothridial setae sc 1 filiform, very long, reaching to insertions of opisthosomal setae d 1. Cheliceral digits smooth along masticatory surface, prebasal laterodorsal fissure located proximad of insertion of proximal cheliceral seta; proximal cheliceral seta inserted distad of articulation of cheliceral digits. Palpal tarsus longer than femorogenu, with small apical tubercle, and with twelve to thirteen long pubescent setae and one spiniform solenidion. Coxae I, II, III, IV with 3-1-5(6)-3(4) finely pubescent setae, respectively. Neotrichy in genital region: six and eight pairs of genital and aggenital setae, respectively. Rhagidial organ I comprised of three short rhagidial solenidia (ω) lying in tandem in separate depressions; stellate famulus (ε) subtending proximal rhagidial solenidion; rhagidial organ II comprised of three short rhagidial solenidia (ω) lying in tandem in confluent depressions, small spiniform famulus (ε) subtending proximal rhagidial solenidion.

Affinities

Adults of Traegaardhia dalmatina differ from the other known Traegaardhia species in the rhagidial organs I and II comprised of only three rhagidial solenidia lying in tandem.

Etymology

The epithet dalmatina indicates the country Dalmatia ( Croatia) where the mite was discovered in a cave near Krivosije ( Willmann 1939). Feminine gender.

Redescription (based on specimens from Ariège, France)

Adult male (three examined). Length of idiosoma 1301(1232–1392) µm. Ratio of leg I length to idiosomal length 1.69(1.57–1.78).

Gnathosoma . Subcapitulum moderately slender, subtriangular ( Fig. 3C); ratio of length to breadth 1.31(1.25–1.38); distal hypostomal lips with spiniform internal and serrate external malar processes; adoral setae nude, long, overlapping apex of subcapitulum; proximal subcapitular setae pubescent, external pair the same length as internal pair. Dorsal surface of chelicera with shallow saddle-shaped depression at level of bases of digits ( Fig. 3A,B); cheliceral digits long, slender; dorsal surface of fixed digit with distinct short narrow rim laterad of insertion of distal cheliceral seta (see in lateral aspect); fixed digit terminates in three cusps, smooth along masticatory surface and with distinct prebasal laterodorsal fissure located proximad of insertion of proximal cheliceral seta and near masticatory surface of fixed digit; movable digit smooth along masticatory surface. Chelicerae with two setae; proximal seta inserted distad of articulation of movable digit; tip of proximal seta not reaching insertion of distal seta; tip of distal seta overlaps apex of fixed digit. Length of chelicera 336(323–363) µm, dorsoventral width 108(105–112) µm, length of movable digit 131(125–138) µm, length of proximal and distal cheliceral setae 33 and 77(69–82) µm, respectively, distance between their insertions 36(33–39) µm. Ratios: cheliceral length to dorsoventral width 3.11(3.0–3.23), length of movable digit to length of chelicera 0.38–0.39, length of movable digit to dorsoventral width of chelicera 1.21(1.19–1.23). Palpal tarsus longer than femorogenu and with small apical tubercle ( Fig. 3D,E); ratio of length to width of tarsus 5.81(5.42–6.36). Length of palpal trochanter, femorogenu, tibia and tarsus 54(46–59), 170(132–198), 91(86– 102) and 223(214–231) µm, respectively. Number of setae and solenidia (in brackets) on palpal trochanter, femorogenu, tibia and tarsus 0-2-3-13(1), respectively; tarsal solenidion spiniform, erect.

Prodorsum. Naso short, with pair of internal vertical setae v 1, protrudes from prodorsum only slightly ( Fig. 2A). Bothridial setae sc 1 filiform, finely pubescent, very long, reaching to insertions of opisthosomal setae d 1. Length of setae: v 1 96(92–99), v 2 135(125–148), sc 1 319(313–323), sc 2 219(198–254) µm.

Opisthosomal dorsum and anal region. Cupules were not discernible on the very fine tegument; setae c 1, d 1, e 1 reach about half of distance to insertion of successive seta ( Fig. 2A); seta f 1 reaches almost to insertion of h 1. Length of setae: c 1 109(99–115), c 2 242(231–254), d 1 98(92–102), e 1 102(96–109), f 1 144(138–148), f 2 91(89–99), h 1 202(198–211), h 2 105(96–115), ps 1 153(145–165), ps 2 93(82–99), ps 3 67(59–76), ad 1 65(57–75) µm.

Podosoma. Coxae I, II, III, IV with 3-1-6-3 finely pubescent setae, respectively.

Genital region. Genital valves each with six finely pubescent genital setae (g) of similar length ( Fig. 2B), about 38(33–46) µm, arranged evenly along medial edge of valve. Eight pairs of aggenital setae (ag), about 87(72–99) µm; sometimes also seven and eight aggenitals asymmetrically. Length of genital valves 142(125– 152) µm. Sperm sac (ss) club-shaped, showing through tegument.

Legs. Leg I 2208 (2144–2288) µm long, about 1.69(1.57–1.78) as long as idiosoma. Empodia of all legs setulose, longer than claws; claws each with small clawlet ventrobasally ( Fig. 3H). Number of setae and solenidia (solenidia and famulus (ε) bracketed), respectively, on legs I-II-III-IV: trochanters 1-1-2-2, basifemora+telofemora 5+5-6+5-4+4-5+4, genua 10(1)-9(1)-6(1)-6, tibiae 11(2)-8(2)-7(2)-6(1), tarsi 19(3+ε)− 16(3+ε)−15−14. Solenidia on leg segments small to minute (Figs 4,5). Genua I and II each with one erect spiniform distoventral solenidion (σ); genu III with one small spiniform medioventral solenidion. Tibia I with one erect spiniform dorsoproximal solenidion (Φ), and one dorsodistal rhagidial solenidion; tibia II with one spiniform erect dorsoproximal solenidion, and one lanceolate dorsodistal solenidion recessed in deep pit with small surface pore ( Fig. 3G); tibia III with two adjacent erect spiniform lateromedial solenidia; tibia IV with one erect spiniform mediolateral solenidion. Tarsus I slender, its tip slightly tapers in lateral view, ratio length to width 10(8.75–11.33), with three rhagidial solenidia (ω) lying in tandem in separate depressions dorsodistally; stellate famulus (ε) subtending proximal rhagidial solenidion ( Fig.3I); tarsus II with three rhagidial solenidia lying in tandem in confluent depressions, small spiniform famulus (ε) subtending proximal rhagidial solenidion ( Fig. 3J,K) .

Adult female (two examined). Length of idiosoma 1392(1280–1504) µm; numerous pubescent eugenital setae on telescopically retracted ovipositor showing through tegument of genital valves. Otherwise as in male.

Remarks

Adults of Traegaardhia dalmatina can be accurately identified according to Willmann´s original description ( Willmann 1939). Three rhagidial solenidia in the rhagidial organ I and II are typical of adults in this species. Cooreman (1959) determined this mite probably erroneously as Rhagidia longipes Trägardh, 1912 although he also pointed out only three rhagidial solenidia in the rhagidial organ I in his specimens originating from caves in Ariège, Cassis and the Maritime Alps, France.

Rhagidia longipes was originally described by Trägardh (1912) only briefly as Rhagidia gigas (Canestrini) var. longipes and no reliable diagnostic characters were given in the original description to identify unambiguously the species. Trägardh (1912: 610.) admitted that he examined a heterogenous material that consisted of a few similar species: “... legs I and IV are more than twice as long as the body, while in the main form (i.e., R. gigas ) they are of the same length as the body. This is, however, not the case in specimens from all caves”. However, it is highly probable that Trägardh examined also some specimens of T. dalmatina because his material originated from caves in the French Pyrenees, Ariège, Ardeche. However, the identity of Trägardh´s material of Rhagidia longipes still remains obscure. In contrast, the Willmann´s morphological concept of T. dalmatina is clear and for that reason we use the specific name dalmatina Willmann (1939) . Morphometric data on specimens of T. dalmatina deposited in the collection of Carl Willmann were already presented and discussed by Zacharda (1980).

It is documented that the morphospecies dalmatina occurs not only in caves of Krivosije, Croatia, but also in the southwestern France (the Pyrenees, Ariège, Cassis). However, one must take into consideration that the geographically outlying populations in French Pyrenees and Dalmatia may be different individual lineages and cryptic species (cf., e.g., Culver & Pipan 2009:144.).

In T. dalmatina the elongated cheliceral digits, palpal tarsi and legs as well as the fine, elongated trichobothria are distinct adaptive troglomorphisms which indicate, together with occurrence in caves, the troglobiont.